1. Field of the Invention
The invention pertains to a closing device for performing closing functions especially in motor vehicles.
2. Description of the Related Art
In comparison with similar closing devices of the older design (DE 44 12 609 A1), devices of this type (DE 198 53 543 A1, DE 197 49 329 C1) offer the advantage of being more compact in the axial direction.
The closing cylinder of these known devices (DE 198 53 543 A1, DE 197 49 329 C1) has only a single key withdrawal position, that is, only one position in which the key can be inserted freely into the cylinder core and pulled back out again. In DE 198-53,543 A1, for example, the key withdrawal position is in the starting position of the closing cylinder, which is determined for a defined rotational angle of the cylinder core by an impulse spring of the return spring. By rotating the key, the cylinder core can be moved to various other positions, which correspond to various other working positions of the working element.
In many practical applications, there is a need to be able to insert and withdraw the key in other rotational positions of the cylinder core. Thus, for example, in the case of the closing devices on the rear sliding or swinging doors or lids of motor vehicles, it is desirable to have the ability to pull the key out both in the starting position of the closing cylinder, i.e., when the lock is open, and also in a rotational position of the cylinder core characterizing the locked position of the lock. In the case of the known devices of the present type, it did not seem possible to realize this goal with an acceptable amount of effort.
The invention is based on the task of developing an inexpensive, reliable device of the type indicated in the introductory clause, which has at least two key-withdrawal positions rotationally offset from each other and which nevertheless have a compact design. This is accomplished according to the invention by the measures listed below, to which the following special meaning belongs:
In the normal case, the coupling slider is engaged with the cylinder core, so that, when the cylinder core is rotated by the turning of the key, the slider is carried along between one of the desired key withdrawal positions and at least one other key withdrawal position, thus arriving at one of the rotationally offset angles thus determined. In addition, several locking control elements are provided according to the invention, one of which is assigned to each of the rotational angles determining the various key withdrawal positions. On transition from the normal case to the overload case, the locking control elements move in the radial direction, as in the case of the devices of the type described in the introductory clause; this radial movement is transmitted to the coupling slider via an axial connection. In the invention, the radial movement of these rotationally offset radial elements occurs in the same direction as the associated rotational angle of the coupling slider when it is in one of the various key withdrawal positions. In the case of the device according to the invention, therefore, only a single coupling slider is needed, which, as a function of the selected key withdrawal position, cooperates with the locking control element or control elements assigned to it at the rotational angle in question, whereas none of the other locking elements participates in the overload case.
Additional measures and advantages of the invention can be derived from the following description, and especially from the drawings. The drawings illustrate the invention on the basis of a closing device unit comprising the closing cylinder, which is shown in various working positions: